Method for Measuring the Magnetic Saturation Profiles of a Synchronous Machine, and Device for the Open-Loop and Closed-Loop Control of an Induction Machine

Abstract

A method for measuring magnetic saturation profiles of a synchronous machine having a rotor and a stator includes actuating the synchronous machine with clocked terminal voltages according to a pulse width modulation process. The method further includes cyclically measuring a current of the synchronous machine resulting from the synchronous machine being actuated by the clocked terminal voltages. The method further includes applying macroscopic flux pulses which allow the current to momentarily increase into a range that can change a magnetic saturation state of the synchronous machine.

What is claimed is: 
     
         1 . A method for measuring magnetic saturation profiles of a synchronous machine having a rotor and a stator, the method comprising:
 actuating the synchronous machine with clocked terminal voltages according to a pulse width modulation process;   cyclically measuring a current of the synchronous machine resulting from the synchronous machine being actuated by the clocked terminal voltages; and   applying macroscopic flux pulses which allow the current to momentarily increase into a range that can change a magnetic saturation state of the synchronous machine.   
     
     
         2 . The method of  claim 1  further comprising:
 assigning values of the macroscopic flux pulse and of the measured resulting current to one another as an operating point data pair and storing the operating point data pair in a table. 
 
     
     
         3 . The method of  claim 1  further comprising:
 immediately after each macroscopic flux pulse, applying multiple microscopic flux pulses which are different from one another, have a sum of zero, and which in their shape and configuration form an injection pattern, wherein the magnetic saturation state of the synchronous machine remains unchanged after the microscopic flux pulses have been applied. 
 
     
     
         4 . The method of  claim 3  wherein:
 the microscopic flux pulses all have the same magnitude and are all orthogonal or antiparallel with respect to one another so that the injection pattern is a square. 
 
     
     
         5 . The method of  claim 3  further comprising:
 calculating local admittance or inductance entries based on the current response to the injection pattern; and 
 storing the calculated local admittance or inductance entries in a table. 
 
     
     
         6 . The method of  claim 2  further comprising:
 applying a plurality of macroscopic flux pulses having various d and q components; and 
 storing resulting operating point data pairs in the table. 
 
     
     
         7 . The method of  claim 1  further comprising:
 applying, after each of the macroscopic flux pulses, an associated compensation pulse that has the same d component and a negated q component to minimize resulting angular momentum. 
 
     
     
         8 . The method of  claim 1  further comprising:
 applying, prior to each macroscopic flux pulse, a direct current in the range of nominal current in a defined direction until a resulting oscillating motion has died down and the rotor is aligned with the current. 
 
     
     
         9 . The method of  claim 2  further comprising:
 calculating rotor position assignment parameters by interpolation, using operating point data pair entries in the table. 
 
     
     
         10 . The method of  claim 2  further comprising:
 deriving unambiguous rotor position assignment parameters from operating point data pair entries in the table by interpolation. 
 
     
     
         11 . A device for open-loop and closed-loop control of an induction machine having a stator and a rotor, the device comprising:
 a controllable pulse width modulation (PWM) converter for outputting clocked terminal voltages;   an apparatus for detecting current; and   a controller configured to control the PWM converter to actuate the induction machine with the clocked terminal voltages, control the apparatus to cyclically measure a current of the induction machine resulting from the induction machine being actuated by the clocked terminal voltages, and apply macroscopic flux pulses which allow the current to momentarily increase into a range that can change a magnetic saturation state of the induction machine.   
     
     
         12 . A synchronous machine comprising a stator, a rotor with or without permanent magnets, and the device of  claim 11 .